In modern internal combustion engines, devices for variably setting the control times of gas exchange valves are used in order to be able to variably configure the phase relation between crankshaft and camshaft within a defined angular range between a maximum advance position and a maximum retard position. The device is connected fixedly in terms of rotation to a camshaft and has a plurality of pressure chambers, by means of which a phase relation between the crankshaft and the camshaft can be varied in a directed way by the supply or discharge of pressure medium. The supply of pressure medium to and discharge of pressure medium from the pressure chambers are controlled by means of a control valve.
A device and a control valve are known, for example, from DE 102 11 468 A1. The device comprises a driven element which is arranged rotatably with respect to a drive element and which is connected fixedly in terms of rotation to a camshaft. The drive element is drive-connected to a crankshaft. Inside the device, a plurality of pressure chambers acting opposite to one another are provided, by means of which the phase position of the driven element in relation to the drive element can be set in a directed way within a defined angular range. Directed rotation of the camshaft in relation to the crankshaft can thus be brought about. In DE 102 11 468 A1, the device is of vane type design. However, other forms of construction, such as axial piston adjusters from DE 42 18 082 A1, are also known.
The camshaft is mounted in a cylinder head of the internal combustion engine by means of a plurality of camshaft bearings. Pressure medium is supplied via one of the camshaft bearings to a pressure medium duct formed in the camshaft and can be conducted into the pressure chambers via a control valve which is arranged in a receptacle of the camshaft. The control valve is composed of a valve housing and of a control piston received axially displaceably in the valve housing. The control piston can be positioned in relation to the valve housing in the axial direction, counter to the force of a spring element, by means of an electromagnetic actuating unit and the pressure medium streams are thus controlled.